1. Field of the Invention
The present invention relates to a digital audio-video (AV) reproducing apparatus and a reproducing method thereof, and more particularly, to a digital AV information reproducing apparatus and a reproducing method thereof, in which a file-based AV file can be reproduced from any time point by generating an “AV index”.
2. Description of the Related Art
Optical disks are advantageous in large capacity, easy and long time of preservation, low cost, and good data protection, and thus optical disks have become one of the mainstreams of modern storage medium. For example, a digital versatile disk (DVD) containing the AV reproducing information such as video, audio, and subtitle as well as the reproducing control information is one example of the optical disks.
For home entertainment environment, it is very common to use a digital AV information reproducing apparatus (e.g. a DVD player) to reproduce a DVD or a file-based digital AV file (e.g. a digital AV file in a format of MPEG4 (moving picture expert group-4)), such that users can watch the AV content.
FIG. 1 schematically shows a block diagram of a conventional DVD player. Referring to FIG. 1, the conventional DVD player 200 comprises a navigator 210, a de-multiplexer 220, a decoder 230, an audio process unit 240, an audio output unit 250, a video process unit 260, a video output unit 270, a user interface 280, and a controller module 290. Wherein, the controller module 290 provides a reproducing control signal to the navigator 210 based on the signal input by the user, and the navigator 210 reads an AV data from an optical disk 100 based on the reproducing control signal.
The de-multiplexer 220 divides the AV data into audio data, video data, and sub-picture units (SPU). Wherein, the audio data, the video data, and the sub-picture units are fed into an audio decoder 232, a video decoder 234, and a sub-picture decoder 236 of the decoder 230, respectively. More specifically, the sub-picture decoder 236 decodes and generates a subtitle picture as well as reproducing information of the subtitle picture (which includes information of time, position, and color contrast, etc) based on the sub-picture unit. Here, the subtitle picture is generally in a bitmap format.
After the video process unit 260 receives the subtitle picture from the sub-picture decoder 236, the subtitle picture is combined with an image output from the video decoder 234. In addition, the audio decoder 232, the video decoder 234, and the sub-picture decoder 236 determines its output time based on a system clock. In general, the DVD player uses a reproducing time of the video data or the audio data as its control basic. To be noted, the navigator 210 may further receive plug-in subtitle information, such that the subtitle with different language can be displayed on the screen. In addition, the AV data of the optical disk 100 further comprises Line-21 information, which provides the subtitle information. Wherein, the so-called Line-21 information represents the information embedded in Line-21.
When the conventional DVD player is reproducing a DVD movie, it can reproduce the DVD movie from any time point. However, when the conventional DVD player is playing the file-based digital AV file, it can only support simple reproducing function, such as rewind, speed forward, and slow picture, etc, and not able to reproduce the digital AV file from any time point. It is because the file-based digital AV file does not contain system layer information, and thus it is not possible to reproduce the digital AV file from any time point. Accordingly, it brings great inconvenience to the user in reproducing the file-based digital AV file. Furthermore, the subtitle is purely displayed when reproducing the AV file and it cannot be used to improve the user interaction.
Accordingly, it is required to provide a digital AV information reproducing apparatus and a method for controlling the same. Even in reproducing the file-based digital AV file, the digital AV file can be reproduced from any time point by using the subtitle as its control basic.